1. Field of the Invention
The present invention generally relates to a light emitting material and a light emitting diode device, in particular, to a light emitting material capable of emitting polarized light and a light emitting diode (LED) device manufactured using the same.
2. Description of Related Art
A light emitting diode (LED) is a semiconductor device that is mainly made of a semiconductor material of III-V group of elements compound. Such a semiconductor material is capable of convert electric energy into light. In specific, when a current is applied to such a semiconductor material, electrons within the semiconductor material combine with holes, and excess energy is released as light, thereby achieving the light emitting effect.
Since the light emitting phenomenon of the LED belongs to cold luminescence rather than thermo luminescence or discharge luminescence, the lifespan of the LED may be up to about 100,000 hours, and no idling time is required. In addition, due to such advantages of quick response time, small volume, low power consumption, low pollution (mercury free), high reliability and suitable for mass production, the LED can be applied in a wide variety of fields, such as scanner light sources requiring for a fast response, back lights of liquid crystal displays (LCDs), illumination for instrument panels of vehicles, traffic signal lamps, and ordinary illuminators.
For back lights of LCDs, the LCDs need to use polarized light as the display light source. Although the advantages of the LED such as small volume, low power consumption and capable of mass production enable the LCDs to be considerably convenient and competitive, all light sources available on the market, including the LED, are suitable for emitting non-polarized light. Therefore, when designing an LCD, a polarizing plate has to be disposed between the back light and an LCD panel. In such a manner, the volume and fabricating cost of the LCDs cannot be further reduced.